- Patients must have had 1 or 2 prior chemotherapy regimens (pre-induction and autologous bone marrow transplantation will be considered as one prior therapy) for lymphoma; this includes investigational agents and/or other antibody therapies; all prior therapy must have been completed at least 2 weeks prior to registration; due to possible interactions with the rituximab antibody; patients previously receiving rituximab must have completed rituximab therapy at least 12 weeks prior to registration; if rituximab is given as a single agent after a relapse, it is considered a separate regimen and will be counted as such; if the rituximab is given in combination for either the first or second relapse or as consolidation after chemotherapy regimen without an intervening relapse, it will be considered part of the combination regimen and counted as one prior therapy; patients must have recovered from any chemotherapy-related toxicities prior to registration